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Abstract:

In one exemplary embodiment, an exhaust dilution and dispersion device
for a vehicle can include a generally elongate tailpipe comprising an
inlet section capable of being in exhaust receiving communication with an
exhaust system of a vehicle. The tailpipe further comprises an outlet
section in exhaust receiving communication with the inlet section. The
outlet section can also comprise a downwardly directed exhaust deflection
portion and an exhaust outlet in exhaust dispersing communication with
the surroundings external to the device. The exhaust outlet can comprise
a generally elongate exhaust dispersion opening extending in a lengthwise
direction along the tailpipe. At least a portion of the exhaust outlet
can be coextensive with the downwardly directed exhaust deflecting
portion and a major portion of the exhaust dispersed from the outlet can
have a transverse component.

Claims:

1. An exhaust dilution and dispersion device for a vehicle, comprising: a
generally elongate tailpipe comprising: (i) an inlet section capable of
being in exhaust receiving communication with an exhaust system of a
vehicle; and (ii) an outlet section in exhaust receiving communication
with the inlet section, the outlet section comprising a downwardly
directed exhaust deflection portion and an exhaust outlet in exhaust
dispersing communication with the surroundings external to the device,
the exhaust outlet comprising a generally elongate opening extending in a
lengthwise direction; wherein at least a portion of the exhaust outlet is
coextensive with the downwardly directed exhaust deflection portion, and
wherein a major portion of the exhaust dispersed from the exhaust outlet
has a transverse component.

2. The exhaust dilution and dispersion device of claim 1, wherein the
tailpipe comprises a length of pipe having a generally cylindrical shape
with a major diameter, and wherein the elongate opening has a width that
is at least approximately 75% of the major diameter of the tailpipe.

3. The exhaust dilution and dispersion device of claim 1, wherein the
length of the elongate opening is at least approximately 1.5 times the
height of the elongate opening.

4. The exhaust dilution and dispersion device of claim 1, wherein the
length of the elongate opening is at least approximately 1.5 times the
width of the elongate opening.

5. The exhaust dilution and dispersion device of claim 1, wherein the
tailpipe comprises a length of pipe having a generally cylindrical shape
with a major diameter, and wherein in profile the elongate opening has a
height that is at least approximately 25% of the major diameter of the
tailpipe.

6. The exhaust dilution and dispersion device of claim 1, wherein a
substantial portion of the perimeter of the elongate opening extends
approximately parallel to a central axis of the tailpipe.

7. The exhaust dilution and dispersion device of claim 1, wherein the
elongate opening has a generally elongate inverted U-shaped side profile.

8. The exhaust dilution and dispersion device of claim 1, wherein the
tailpipe comprises an inlet section end and an outlet section end, and
wherein the downwardly directed exhaust deflection portion proximate the
outlet section end defines an angle of between approximately 130.degree.
and approximately 150.degree. with respect to a central axis of the
tailpipe.

10. The exhaust dilution and dispersion device of claim 9, wherein the
bifurcated section has at least one symmetry plane.

11. The exhaust dilution and dispersion device of claim 9, wherein an
interior surface of the at least one deflector is generally convex and an
interior surface of the at least one exhaust flow guide is generally
concave.

14. The exhaust dilution and dispersion device of claim 1, further
comprising a nozzle having a first inlet end portion connectable to an
exhaust system of a vehicle and a second exhaust acceleration end portion
generally opposite the first inlet end portion, the second exhaust
acceleration end portion comprising reduced cross-sectional areas in an
exhaust flow direction, wherein the second exhaust acceleration end
portion of the nozzle is at least partially disposed within the inlet
section of the tailpipe such that an ambient air passageway is defined
between an outer surface of the nozzle and an inner surface of the
tailpipe, the air passageway facilitating passage of ambient air from the
surroundings into exhaust flowing through the tailpipe.

15. The exhaust dilution and dispersion device of claim 14, wherein the
tailpipe has an overall length, and wherein the exhaust outlet has a
length that is at least approximately 50% of the length of the tailpipe.

16. The exhaust dilution and dispersion device of claim 14, wherein the
inlet section of the tailpipe comprises a diffusion section having
increasing cross-sectional areas in the exhaust flow direction.

17. The exhaust dilution and dispersion device of claim 14, further
comprising a plurality of connection structures coaxially coupling the
nozzle and the tailpipe, the connection structures being generally
elongated and extending in a direction generally parallel to a central
axis of the nozzle and the tailpipe.

18. The exhaust dilution and dispersion device of claim 14, further
comprising a plurality of connection structures coaxially coupling the
nozzle and the tailpipe together, at least one of the connection
structures being generally elongated and having a turbulence inducing
portion that is not parallel to a central axis of the tailpipe.

19. The exhaust dilution and dispersion device of claim 14, wherein the
ambient air passageway is generally annularly-shaped.

20. An exhaust cooling tailpipe for a vehicle, comprising: a first
generally tubular inlet portion with an exhaust inlet capable of being in
exhaust receiving communication with an exhaust system of a vehicle; and
a second outlet portion coupled to the inlet portion and comprising: (i)
a downwardly directed exhaust deflection portion having at least one
inwardly projecting deflector with increasing interior surface areas in
an exhaust flow direction and at least one outwardly projecting exhaust
flow guide with decreasing cross-sectional areas in the exhaust flow
direction; and (ii) an exhaust outlet in exhaust dispersing communication
with the environment, the exhaust outlet comprising a generally elongate
opening extending longitudinally along the tailpipe, the opening being at
least partially coextensive with the downwardly directed exhaust
deflection portion such that at least a major portion of the exhaust
being dispersed through the opening has a sideways component.

21. The exhaust cooling tailpipe of claim 20, wherein a substantial
portion of the perimeter of the exhaust outlet opening extends
approximately parallel to a central axis of the tailpipe.

22. The exhaust cooling tailpipe of claim 20, wherein an inner surface of
the inwardly projecting deflector defines an angle of between
approximately 130.degree. and approximately 150.degree. with respect to a
central axis of the tailpipe.

23. The exhaust cooling tailpipe of claim 20, wherein the tailpipe
comprises a length of pipe having a generally cylindrical shape with a
major diameter, and wherein the exhaust outlet opening has a width that
is at least approximately 75% of the major diameter of the tailpipe.

24. The exhaust cooling tailpipe of claim 20, wherein the length of the
elongate opening is at least approximately 1.5 times the width of the
elongate opening.

25. The exhaust cooling tailpipe of claim 20, wherein the tailpipe
comprises a length of pipe having a generally cylindrical shape with a
major diameter, and wherein in profile the exhaust outlet opening has a
height that is at least approximately 25% of the major diameter of the
tailpipe.

26. An exhaust dilution and dispersion device for a vehicle, comprising:
an exhaust acceleration portion configured for mounting in exhaust
receiving communication with a vehicle, the acceleration portion having
an exhaust acceleration passage with reduced cross-sectional areas in an
exhaust flow direction; an exhaust diffusion portion in exhaust receiving
communication with the exhaust accelerating passage of the exhaust
accelerating portion, the exhaust diffusion portion having an exhaust
diffusion passage with increased cross-sectional areas in the exhaust
flow direction; an air passageway having an inlet communicating with
ambient air and an outlet communicating with the exhaust diffusion
portion; and an exhaust dispersion portion in exhaust receiving
communication with the exhaust diffusion passage and having a generally
elongate exhaust dispersion opening extending in a lengthwise direction
and in exhaust expelling communication with a surrounding environment,
the elongate exhaust dispersion opening laterally dispersing at least a
major portion of exhaust flowing through the exhaust dispersion portion.

27. The exhaust dilution and dispersion device of claim 26, wherein the
exhaust dispersion opening has a generally elongate arcuate-shaped side
profile.

28. The exhaust dilution and dispersion device of claim 26, wherein the
exhaust acceleration passage is coaxial with and at least partially
positioned within the exhaust diffusion passage of the exhaust diffusion
portion, and wherein the air passageway comprises a generally
annularly-shaped passage formed between the exhaust accelerating portion
and the exhaust diffusion portion.

29. The exhaust dilution and dispersion device of claim 28, wherein the
exhaust acceleration portion is coupled to the exhaust diffusion portion
via a plurality of gussets.

30. The exhaust dilution and dispersion device of claim 26, wherein the
exhaust acceleration portion comprises a first generally tubular-shaped
pipe and the exhaust diffusion portion comprises a second generally
tubular-shaped pipe, and wherein the first generally tubular-shaped pipe
is positioned at least partially within the second generally
tubular-shaped pipe, wherein the air passageway comprises a space defined
between the first pipe and the second pipe.

31. The exhaust dilution and dispersion device of claim 30, wherein the
first generally tubular-shaped pipe has an inlet end and an outlet end,
wherein the inlet end is capable of being placed in exhaust receiving
communication with a vehicle exhaust system of a vehicle and the outlet
end is in exhaust expelling communication with the second generally
tubular-shaped pipe.

32. The exhaust dilution and dispersion device of claim 26, wherein the
device further comprises an exhaust mixing portion intermediate the
exhaust diffusion portion and the exhaust dispersion portion, the mixing
portion having a passageway with a side wall generally parallel to the
exhaust flow direction, the mixing portion being in exhaust receiving
communication with the diffusion portion and exhaust expelling
communication with the exhaust dispersion portion.

33. A method of cooling exhaust from a vehicle, comprising: receiving a
flow of exhaust from an exhaust system of a vehicle; downwardly
deflecting at least a portion of the flow of exhaust; and dispersing the
flow of exhaust away from the vehicle, wherein dispersing the flow of
exhaust comprises downwardly dispersing the flow of exhaust and laterally
dispersing at least a major portion of the flow of exhaust.

34. The method of claim 33, further comprising bifurcating at least a
portion of the flow of exhaust.

35. The method of claim 33, further comprising accelerating the flow of
exhaust received from the exhaust system and mixing ambient air with the
flow of exhaust prior to dispersing the exhaust.

36. The method of claim 35, further comprising decelerating the flow of
exhaust after mixing ambient air with the flow of exhaust.

Description:

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of U.S. application Ser. No.
11/442,365, entitled VEHICLE EXHAUST DILUTION AND DISPERSION DEVICE,
filed on May 26, 2006, and further claims the benefit of U.S. Provisional
Application No. 60/709,039, entitled VEHICLE EXHAUST DILUTION AND
DISPERSION DEVICE, filed Aug. 16, 2005, and U.S. Provisional Application
No. 60/765,238, entitled TAILPIPE EXHAUST HEAT MITIGATION DEVICE, filed
Feb. 3, 2006, all of which are incorporated herein by reference.

FIELD

[0002] This invention relates to an exhaust system for a vehicle, and in
particular, a vehicle exhaust dilution and dispersion device.

BACKGROUND

[0003] The temperature of exhaust dispersed from a vehicle's tailpipe
outlet at a certain distance away from the outlet must meet certain
industry safety standards.

[0004] Some modern internal combustion engines for use with vehicles, such
as diesel engines, are being equipped with devices to burn particulates
in exhaust gases to reduce environmental pollutants. Use of such devices
can result in hotter exhaust gas than engines running without the
devices. But even without using such a burning device, some modern
engines are operable to produce hotter exhaust gas then older engines.
For example, some engines are or will be capable of producing exhaust gas
at or above 1200° F. Known passive exhaust gas systems may not be
able to sufficiently reduce the exhaust gas temperature to meet industry
standards.

SUMMARY

[0005] The present disclosure is directed toward all new and non-obvious
features and method acts disclosed herein both alone and in novel and
non-obvious combinations and sub-combinations with one another. The
disclosure is not limited to constructions which exhibit all of the
advantages or components disclosed herein. The embodiments set forth
herein provide examples of desirable constructions and are not to be
construed as limiting the breadth of the disclosure.

[0006] Described herein are embodiments of a vehicle exhaust dilution and
dispersion device used as an after-treatment element of a vehicle's
exhaust system. The exhaust dilution and dispersion device can facilitate
a more rapid temperature reduction of exhaust dispersed into the
atmosphere from the exhaust system than conventional exhaust systems.
Since the exhaust dilution and dispersion device preferably provides
temperature reduction characteristics, the vehicle exhaust dilution and
dispersion device can be termed an exhaust cooling device.

[0007] In one exemplary embodiment, an exhaust dilution and dispersion
device for a vehicle can include a generally elongate tailpipe comprising
an inlet section capable of being in exhaust receiving communication with
an exhaust system of a vehicle. The tailpipe further comprises an outlet
section in exhaust receiving communication with the inlet section. The
outlet section can also comprise a downwardly directed exhaust deflection
portion and an exhaust outlet in exhaust dispersing communication with
the surroundings external to the device. The exhaust outlet can comprise
a generally elongate exhaust dispersion opening extending in a lengthwise
direction along the tailpipe. At least a portion of the exhaust outlet
can be coextensive with the downwardly directed exhaust deflecting
portion and a major portion of the exhaust dispersed from the outlet can
have a transverse component.

[0008] In some implementations, the tailpipe can comprise a length of pipe
having a generally cylindrical shape with a major diameter and the
elongate opening can have, for example, a width that is at least
approximately 75% of the major diameter of the tailpipe. In some
implementations, the elongate opening can have a height in a side profile
that is at least approximately 25% of the major diameter of the tailpipe.
In some implementations, the elongate opening can have a length that is
at least approximately 50% of the length of the tailpipe. In yet some
implementations, a substantial portion of the perimeter of the elongate
opening can extend approximately parallel to a central axis of the
tailpipe. In certain implementations, the elongate opening can have a
generally elongate inverted U-shaped profile.

[0009] In some implementations, at an end of the tailpipe, the downwardly
directed exhaust deflection portion can define an angle of between
approximately 130° and approximately 150° with respect to a
central axis of the tailpipe.

[0010] In some implementations, the downwardly directed exhaust deflection
portion can comprise, for example, a bifurcated section having at least
one inwardly projecting deflector and at least one outwardly projecting
exhaust flow guide. In specific implementations, an interior surface of
the at least one deflector can be generally convex and an interior
surface of the at least one exhaust flow guide can be generally concave.
In some implementations, the downwardly directed exhaust deflection
portion can comprise at least two outwardly projecting exhaust flow
guides and one inwardly projecting deflector, where the inwardly
projecting deflector is disposed intermediate the at least two outwardly
projection flow guides. In certain implementations, the bifurcated
section has at least one symmetry plane.

[0011] In some implementations, the downwardly directed exhaust deflection
portion can comprise at least one inwardly projecting deflector having
increasing interior surface areas in an exhaust flow direction and an at
least one outwardly projecting flow guide defining an exhaust flow
channel that has decreasing cross-sectional areas in the exhaust flow
direction.

[0012] In some implementations, the exhaust dilution and dispersion device
can comprise a nozzle having a first exhaust inlet end portion
connectable to an exhaust system of a vehicle and a second exhaust
acceleration end portion generally opposite the first exhaust inlet end
portion and having reduced cross-sectional areas in an exhaust flow
direction. The second exhaust acceleration end portion of the nozzle can
be at least partially disposed within the first end portion of the
tailpipe such that an ambient air passageway is defined between an outer
surface of the nozzle and an interior surface of the tailpipe. This
ambient air passageway can facilitate passage of ambient air from the
surroundings into the exhaust flowing through the tailpipe. In specific
implementations, the ambient air passageway can be, for example,
generally annularly-shaped.

[0013] In specific implementations, the tailpipe can comprise a diffusion
section intermediate the second exhaust accelerating end portion of the
nozzle and the exhaust dispersion opening. The diffusion section can have
increasing cross-sectional areas in the exhaust flow direction.

[0014] In specific implementations, the exhaust dilution and dispersion
device can have a plurality of connection structures, such as gussets,
coaxially coupling the nozzle and the tailpipe together. The connection
structures can be generally elongated and extend in a direction generally
parallel to a central axis of the nozzle. Further, in some
implementations, the connection structures can have a turbulence inducing
portion that is not parallel to a central axis of the tailpipe.

[0015] In another exemplary embodiment, an exhaust cooling tailpipe for a
vehicle can comprise a first generally tubular inlet portion with an
exhaust inlet capable of being in exhaust receiving communication with an
exhaust system of a vehicle and a second outlet portion coupled to the
inlet portion. The second outlet portion can comprise a downwardly
directed exhaust deflection portion having a bifurcated section. The
bifurcated section can have at least one inwardly projecting deflector
with increasing interior surface areas in an exhaust flow direction and
at least one outwardly projecting exhaust flow guide with decreasing
cross-sectional areas in the exhaust flow direction. The deflector can be
coextensive with the at least one flow guide. The second outlet portion
can also comprise an exhaust outlet in exhaust dispersing communication
with the environment. The exhaust outlet can comprise a generally
elongate opening that extends longitudinally along the tailpipe and is
coextensive with the downwardly directed exhaust deflecting portion such
that at least a major portion of the exhaust is dispersed through the
opening in a direction lateral to the tailpipe.

[0016] In one exemplary embodiment, an exhaust dilution and dispersion
device for a vehicle can include an exhaust accelerating portion for
mounting in exhaust receiving communication with a vehicle. The
acceleration portion can have an exhaust acceleration passage of reduced
cross-sectional areas to accelerate the exhaust flow therethrough. The
exhaust acceleration passage can, for example, comprise an exhaust
acceleration section having a passage with converging side walls in an
exhaust flow direction.

[0017] The exhaust dilution and dispersion device can also include an
exhaust diffusion portion in exhaust receiving communication with the
exhaust accelerating passage of the exhaust accelerating portion. The
exhaust diffusion portion can have an expansion portion of increased
cross-sectional area. The exhaust diffusion portion can, for example,
comprise an exhaust diffusion passage of increased cross-sectional areas
to facilitate expansion of the exhaust.

[0018] The exhaust dilution and dispersion device can further include an
air passageway having a first portion communicating with or exposed to
ambient air and a second portion communicating with or exposed to the
exhaust diffusion portion so as to introduce ambient air (air outside the
exhaust dilution and dispersion device) into the exhaust diffusion
portion.

[0019] The device can also include an exhaust dispersion portion in
exhaust receiving communication with the exhaust diffusion passage and
having a generally elongate exhaust dispersion opening extending in a
lengthwise direction and in exhaust expelling communication with the
surrounding environment. The exhaust dispersion opening is configured to
laterally disperse at least a major portion of exhaust.

[0020] In specific implementations, the exhaust dispersion opening can
have a generally elongate arcuate-shaped profile.

[0021] In certain implementations, the exhaust accelerating passage can be
coaxial with and at least partially positioned within the exhaust
diffusion passage of the exhaust diffusion portion. In these
implementations, the air passageway can, for example, include a generally
annularly-shaped passage formed between the exhaust accelerating portion
and the exhaust diffusion portion.

[0022] In some implementations, the exhaust accelerating portion can be
coupled to the exhaust diffusion portion such as via support or coupling
structures with one specific example being a plurality of gussets. In
specific implementations, each of the plurality of gussets can extend
approximately parallel to and in the same general direction as a central
axis of the exhaust accelerating passage and the exhaust diffusion
passage. In other specific implementations, at least one of the plurality
of gussets can extend at an angle relative to, or otherwise not parallel
to, a central axis of the exhaust accelerating passage and the exhaust
diffusion passage.

[0023] In some implementations, the exhaust accelerating portion can
include a first generally tubular-shaped pipe and the exhaust diffusion
portion can include a second generally tubular-shaped pipe. The first
generally tubular-shaped pipe can be positioned at least partially within
the second generally tubular-shaped pipe and the air passageway can
include a space defined between the first pipe and the second pipe. In
certain implementations, the first generally tubular-shaped pipe can have
an inlet end and an outlet end where the inlet end is adapted for
mounting in exhaust receiving communication with a vehicle exhaust system
of the vehicle and the outlet end is in exhaust expelling communication
with the second generally tubular-shaped pipe.

[0024] In some implementations, the exhaust dilution and dispersion device
can include a mixing portion intermediate the exhaust diffusion portion
and the exhaust dispersion portion. The mixing portion can have a
passageway with a side wall generally parallel to the exhaust flow
direction. Further, the mixing portion can be in exhaust receiving
communication with the diffusion portion and exhaust expelling
communication with the exhaust dispersion portion.

[0025] In some implementations, the diffusion portion can be generally
seamlessly connected to the dispersion portion.

[0026] In one exemplary embodiment, a method of cooling exhaust from a
vehicle can comprise receiving a flow of exhaust from an exhaust system
of a vehicle, downwardly deflecting at least a portion of the flow of
exhaust, and dispersing the flow of exhaust away from the vehicle.
Dispersing the flow of exhaust can comprise downwardly dispersing the
flow of exhaust and laterally dispersing at least a major portion of the
flow of exhaust.

[0027] In some implementations, the method can further comprise
bifurcating at least a portion of the flow of exhaust.

[0028] In some implementations, the method can comprise accelerating the
flow of exhaust received from the exhaust system and mixing ambient air
with the flow of exhaust prior to dispersing the exhaust. In specific
implementations, the method can further include decelerating the flow of
exhaust after mixing ambient air with the flow of exhaust.

[0029] The foregoing and other features and advantages will become more
apparent from the following detailed description, which proceeds with
reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The patent or application file contains at least one drawing
executed in color. Copies of this patent or patent application
publication with color drawing(s) will be provided by the Office upon
request and payment of the necessary fee.

[0031]FIG. 1a is a perspective view of an exemplary embodiment of an
exhaust dilution and dispersion device coupled to an exhaust system of a
vehicle.

[0032] FIG. 1b is a perspective view of the exhaust dilution and
dispersion device of FIG. 1a.

[0040] FIG. 9 is a rear view of the device of FIG. 1a shown with exhaust
flow direction indicator arrows.

[0041] FIG. 10 is a perspective view of a known exhaust tailpipe having a
downwardly curved outlet.

[0042] FIG. 11 is a side elevational view of the tailpipe of FIG. 10.

[0043] FIGS. 12a-12c are tables of testing conditions and results for
various tests performed on simulated and physical embodiments of the
devices described herein.

[0044] FIGS. 13a and 13b are color-coded simulated thermal plots for the
exhaust dilution and dispersion device of FIG. 1a and the conventional
tailpipe of FIG. 10, respectively, at a distance of 5.5 inches away from
the outlets of the respective device and tailpipe.

[0045] FIGS. 14a and 14b are color-coded simulated thermal plots for the
exhaust dilution and dispersion device of FIG. 1a and the conventional
tailpipe of FIG. 10, respectively, at a distance of approximately 12
inches away from the outlets of the respective device and tailpipe.

[0046] FIGS. 15a and 15b are color-coded measured thermal plots for the
exhaust dilution and dispersion device of FIG. 1a and the conventional
tailpipe of FIG. 10, respectively, at a distance of approximately 6
inches away from the outlets of the respective device and tailpipe.

[0047] FIGS. 16a and 16b are color-coded measured thermal plots for the
exhaust dilution and dispersion device of FIG. 1a and the conventional
tailpipe of FIG. 10, respectively, at ground level, or at distance of
approximately 16 inches away from the outlets of the respective device
and tailpipe.

[0048] FIGS. 17a and 17b are color-coded predicted thermal plots for the
exhaust dilution and dispersion device of FIG. 1a at approximately 6
inches away from the outlet of the device and at ground level, or
approximately 16 inches away from the outlet of the device, respectively.

[0049] FIG. 18 is a perspective view of an exemplary embodiment of an
exhaust dilution and dispersion device for an exhaust system of a vehicle
having an elongate exhaust dispersion opening and an air entrainment
mechanism.

[0050] FIG. 19 is a side elevational view of the device of FIG. 18.

[0051] FIG. 20 is a cross-sectional side elevational view of the device of
FIG. 18 taken along the line 20-20 in FIG. 18.

[0052] FIG. 21 is an exploded view of the device of FIG. 18 shown with the
gussets removed and respective air and exhaust flow direction indicator
arrows.

[0053] FIG. 22 is a top view of the device of FIG. 18 shown with exhaust
flow direction indicator arrows.

[0054] FIG. 23 is a top view of an exhaust dilution and dispersion device
for an exhaust system of a vehicle having angled turbulence enhancing
gussets.

[0055] FIGS. 24a and 24b are color-coded simulated thermal plots for the
exhaust dilution and dispersion device of FIG. 18 at a distance of 5.5
inches and approximately 12 inches, respectively, away from the outlet of
the device.

[0056] FIGS. 25a and 25b are color-coded measured thermal plots for the
exhaust dilution and dispersion device of FIG. 18 at a distance of
approximately 6 inches away from the outlet of the device and at ground
level, or approximately 16 inches away from the outlet of the device.

[0057] FIGS. 26a and 26b are color-coded predicted thermal plots for the
exhaust dilution and dispersion device of FIG. 18 at a distance of
approximately 6 inches away from the outlet of the device and at ground
level, or approximately 16 inches away from the outlet of the device.

[0058] FIG. 27 is a perspective view of an exemplary embodiment of an
exhaust dilution and dispersion device for an exhaust system of a vehicle
having an elongate exhaust dispersion opening, bifurcated end portion and
an air entrainment mechanism.

[0059] FIG. 28 is a graph showing the backpressure within an engine
exhaust system employing an exhaust dilution and dispersion device versus
an engine exhaust system employing a conventional tailpipe over time.

[0060] In the following detailed description and claims, spacially
orienting terms such as "horizontal," "vertical," "upper," "lower,"
"downwardly" and "upwardly" are used. Unless otherwise noted, it is to be
understood that these terms are for convenience of description with
respect to the drawings and not themselves necessarily limiting of the
orientation of any given component in space.

DETAILED. DESCRIPTION

[0061] An exhaust dilution and dispersion device, e.g., exhaust cooling
device, for diluting and dispersing exhaust from a vehicle's exhaust
system is described herein. As will be described in more detail, the
device can reduce the maximum temperature of exhaust gas dispersed from
the device, such as at a specific distance from the device outlet. The
exhaust dilution and dispersion device can comprise, for example, a
generally elongate, downwardly facing, opening and downwardly directed
deflection portion for producing a wide multi-directional dispersion of
exhaust exiting the opening. In some implementations, the device opening
disperses at least a major portion of exhaust laterally from the device.
The opening can provide many advantages, such as, for example,
accentuated multi-directional dispersion of exhaust gas, additional
engine back-pressure relief and decreased tailpipe weight.

[0062] Referring to FIG. 1a, according to one exemplary implementation, an
exhaust dilution and dispersion device can be coupled to an exhaust
system of a vehicle at any of various locations within or along the
exhaust system. Truck 2, being exemplary of vehicles known in the art,
can include an exhaust system 4 having an after-treatment device, such as
muffler 6, and an exhaust conduit, such as exhaust pipe 8, coupling the
after-treatment device and the vehicle's engine (not shown). Exhaust from
the vehicle's engine flows through the conduit, into the muffler, and
dispersed into the atmosphere. As shown in FIG. 1a, a portion of the
vehicle has been removed to reveal an exhaust dilution and dispersion
device, such as exhaust dilution and dispersion device 10, coupled to the
muffler 6 of the exhaust system 4. In this manner, an exhaust dilution
and dispersion device, such as device 10, can receive exhaust from the
muffler and dilute and disperse it as will be described in more detail
below.

[0063] Although the vehicle shown is a semi-trailer truck 2, it is
recognized that the exhaust dilution and dispersion device, as will be
described in more detail hereafter, can be coupled to the exhaust system
of other types of vehicles including, but not limited to, passenger cars,
tractors, planes and recreational vehicles. The exhaust dilution and
dispersion device of the present disclosure can also be used with
equipment having a combustible engine with an exhaust system, such as,
but not limited to, diesel generators.

[0064] The exhaust dilution and dispersion device can be mounted to a
vehicle or equipment in a variety of orientations. For example, as shown
in FIG. 1a, the exhaust dilution and dispersion device, such as exhaust
dilution and dispersion device 10, can be mounted horizontally relative
to the ground. In other implementations, the exhaust dilution and
dispersion device can be mounted vertically relative to the ground or any
other angle relative to the ground. Also, the device can be mounted in
any of various orientations about its axis such that the device outlet
faces in any of a variety of directions.

[0065] The exhaust dilution and dispersion device can be mounted to a
vehicle or equipment at any of a variety of locations. For example, in
some implementations, such as shown in FIG. 1a, when mounted to a
vehicle, the exhaust dilution and dispersion device can be disposed at a
location approximately midway along the length of the vehicle and below
the frame of the vehicle. It is also recognized that in some
implementations, the exhaust dilution and dispersion device can be
disposed above the frame of the vehicle and can be proximate the top of
the vehicle. The exhaust dilution and dispersion device can be mounted at
an inboard location, e.g., mounted to an interior portion of the vehicle,
or at an outboard location, e.g., mounted to an exterior portion of the
vehicle. Also, the exhaust dilution and dispersion device need not be
positioned midway along the length of a vehicle as shown, but can be
disposed proximate, or anywhere between, the front or rear portions of a
vehicle.

[0066] Referring to FIG. 1b, exhaust dilution and dispersion device 10
comprises a tailpipe, or tailpipe portion, 12 having an exhaust inlet
section, or portion, 13 and an exhaust outlet section, or portion, 18
coupled to the exhaust inlet section. The exhaust inlet section 13
comprises a length of tubing, such as cylindrical tubing having a
generally circular cross-section, and an exhaust inlet opening 35 at a
first end 14 of the tailpipe 12. The exhaust inlet section 13 can be
coupled to a portion of a vehicle's exhaust system by known coupling
techniques, such as by welding or through use of conventional fasteners
or pipe couplings, such that the exhaust inlet opening 35 is in exhaust
receiving communication with the exhaust system of the vehicle. In some
implementations, the exhaust inlet section 13 can include a flanged
portion (not shown) or other portion or attachment proximate the first
end 14 for facilitating coupling the tailpipe 12 to the exhaust system of
a vehicle.

[0067] The exhaust outlet section 18 comprises a neck portion 26 coupled
to the exhaust inlet section 13 and a bifurcated end, deflection, or
baffle, portion 19 coupled to the neck portion. As best shown in FIG. 4,
the neck portion 26 comprises a length of pipe having a generally
semi-circular shaped cross-section. In some implementations, the neck
portion 26 can be seamlessly connected to the tailpipe inlet section 13
and the semi-circular shaped cross-section of the neck portion can be
coextensive with the cross-section of the inlet section. More
specifically, the tailpipe inlet section 13 and the tailpipe outlet
section 18, including the neck portion 26, can be formed from a single
length of pipe to form a monolithic one-piece construction. As perhaps
best shown in FIG. 3, the bifurcated end portion 19 can comprise flared
side portions 24 extending laterally away from the outer periphery of the
neck portion 26.

[0068] In the exemplary embodiment, the bifurcated end portion 19
comprises a formed end having, for example, a pair of exhaust flow guides
20 and a flow guide divider 22 disposed intermediate and separating the
exhaust flow guides 20. The exhaust flow guides 20 and flow guide divider
22 extend from an upper portion of the tailpipe 12 in a downwardly
direction toward the second end 16 of the tailpipe. The innermost
interior surface 28 of the flow guide divider 22 is downwardly directed
in the exhaust flow direction, i.e., a direction extending from the first
end 14 towards the second end 16 of the tailpipe 12, at an angle of
β with respect to a central axis A of the tailpipe 12, i.e., an axis
that is concentric with the tailpipe inlet section 10 (see FIG. 7). In
some implementations, the angle β can be between approximately
90° and approximately 180°. Preferably, in more specific
implementations, the angle β can be between approximately
130° and 150°.

[0069] Perhaps best shown in FIGS. 5 and 6, in the exemplary
implementations, the flow guides 20 and flow guide divider 22 are
seamlessly connected to form a one-piece construction having a generally
"M-shaped" or undulating cross-section. The flow guides 20 can each
comprise, for example, an outwardly directed bump or protrusion and the
flow guide divider 22 can comprise, for example, an inwardly directed
indentation, protrusion or bump. As defined herein, outwardly refers to a
direction extending generally away from the central axis A or,
alternatively, the exhaust flow path and inwardly refers to a direction
extending generally toward the central axis A or, alternatively, into the
exhaust flow path.

[0070] The interior surface of each of the flow guides 20 define an
exhaust flow channel 30 through which a portion of the exhaust flowing
through the tailpipe 12 is allowed to flow. The interior surface of the
flow guides 20 and respective channels 30 can be, for example, generally
concave. In specific implementations, the channels 30 can have decreasing
cross-sectional areas in the exhaust flow direction. The interior surface
of the flow guide divider 22 can be, for example, generally convex to
partition the respective channels 30 of the flow guides 20. As shown, the
flow guide divider 22 can have, for example, increasing lateral major
dimensions or widths, e.g., increasing interior surface areas, moving in
the exhaust flow direction. Although the interior surfaces of the flow
guides 20 and guide divider 22 are concave and convex, respectively, it
is recognized that the interior surfaces can be other than concave and
convex. For example, the interior surfaces can be triangular, rectangular
or polygonal.

[0071] Although two flow guides 20 having a respective channel 30 and one
divider 22 are shown, it is recognized that in some implementations, more
or less than two flow guides 20 can be used and more than one divider 22
can be used. For example, the bifurcated end portion could have a
generally "clam shell" shape or fan-like shape with a plurality of flow
guides and a plurality of dividers each disposed intermediate a
respective pair of the plurality of flow guides.

[0072] The bifurcated end portion 19 shown has at least one symmetrical
plane, i.e., a plane that divides the opening in such a way that the
points on one side of the plane are equivalent to the points on the other
side by reflecting through the plane. For example, in the illustrated
embodiments, a symmetrical plane of the bifurcated end portion 19 is a
vertical plane extending parallel to and through axis A. Although in the
preferred embodiments, the bifurcated end portion has a plane of
symmetry, it is recognized that in some embodiments, the bifurcated end
portion need not have a plane of symmetry. For example, in certain
applications, e.g., where it is desirable to disperse more exhaust to one
side of the device than the other, the bifurcated end portion could have,
for example, one flow guide 20 on a first side of the bifurcated end
portion and two or more flow guides 20 on a second side of the bifurcated
end portion, or a flow guide divider 22 that is off-set with respect to
axis A.

[0073] The outlet section 18 of the device 10 includes an elongate exhaust
dispersion opening 43 extending longitudinally from the neck portion 16
to the second end 16 of the tailpipe. Preferably, at least a portion of
the exhaust dispersion opening is coextensive with or adjacent the
bifurcated end portion 19. As used herein, coextensive can be defined
generally to mean in close proximity or sharing a general boundary, edge,
or space. As used herein, coextensive can also mean adjacent or
adjoining, but is not limited to direct contact.

[0074] The exhaust dispersion opening 43 can face in a generally downward
direction and can have a side-view profile defining one of many shapes.
Preferably, the exhaust dispersion opening 43 is symmetrical with respect
to at least one symmetry plane. For example, in the illustrated
embodiments, the opening 43 has a symmetry plane extending parallel to
and through axis A. For example, as best shown in FIG. 2, exhaust
dispersion opening 43 has a generally elongate arcuate-shaped, or
elongate inverted U-shaped, side profile. The symmetrical edges defining
the exhaust dispersion opening 43 can extend upwardly at an angle
relative to axis A from a first location 32 proximate a lowermost surface
of the neck portion 26 toward a second location 34 away from the first
location 32 moving in the exhaust flow direction.

[0075] The edges then extend approximately parallel to axis A and along a
lower boundary of the neck portion 26 and the flared side portions 24 in
the exhaust flow direction from the second location 34 to a third
location 36. Preferably, the junction between the angled edges extending
from the first location 32 to the second location 34 and the edges
extending from the second location 34 and the third location 36 is
radiused to reduce stress and help prevent stress fractures from
occurring in the tailpipe.

[0076] From the third location 36, the edges angle downwardly relative to
axis A moving in the exhaust flow direction to a fourth location 38
proximate the second end 16 of the tailpipe 12. At least a portion of the
edges extending from the third location 36 to the fourth location 38
adjoins a respective exhaust flow guide 20. As shown in the illustrated
embodiments, at the approximate intersection between angled edges of the
opening 43 and edges of the opening 43 extending generally parallel to
axis A, the edges can be radiused or curved.

[0077] In some embodiments, each of the two generally symmetrical edges
extending approximately parallel to axis A between the second and third
locations 34, 36 comprises a substantial portion of the perimeter of the
opening 43, i.e., each edge has a length of at least approximately 15% of
the total length LO of the opening 43. The total length LO of
the opening 43 can be defined as the distance between the first location
32 and the fourth location 38 extending axially along the opening 43. In
some specific implementations, each edge extending from the second
location 34 to the third location 36 can have a length of at least
approximately 50% of the total length LO of the opening 43.

[0078] Although in the preferred embodiments, the exhaust outlet opening
of the exhaust dilution and dispersion device described herein, e.g.,
opening 43 of tailpipe 12, is symmetrical, i.e., has at least one
symmetrical plane, it is recognized that in some embodiments, the exhaust
outlet opening is not symmetrical, i.e., does not have a plane of
symmetry.

[0079] The edges of the flow guides 20 and the flow guide divider 22 at
the second end 16 of the tailpipe 12 can, for example, define a lower
edge 40 of the second end (see FIG. 2). In the preferred embodiments, the
flow guides 20 and flow guide divider 22 extend downwardly a distance
such that the lower edge 40 of the second end 16 is lower than the first
location 32, e.g., the lowermost surface of the neck portion 26. In one
specific implementation, the lower edge 40 of the second end 16 extends
lower than the lowermost surface of the neck portion a distance equal to
approximately 10% of the interior diameter of the neck portion. In some
implementations, the lower edge 40 of the second end 16 of the tailpipe
12 is generally horizontally disposed, e.g., parallel to axis A.

[0080] In some implementations, the second and third locations 34, 36,
respectively, are at an elevation approximately equal to the elevation of
axis A. Accordingly, in this example, the edges defining the exhaust
dispersion opening 43 between the second and third locations 34, 36 can
extend at an elevation approximately equal to the elevation of the axis
A. In other words, the height H of the opening 43 can be approximately
equal to half the diameter D of the inlet portion 13 (see FIG. 2). The
height H of the opening 43 can be defined as the vertical distance
between the lower of the first location 32 and the fourth location 38,
and the higher of the second location 34 and the third location 36.

[0081] In certain implementations, the edges defining the exhaust
dispersion opening 43 extend to an elevation below the elevation of axis
A. For example, the height H of the opening 43 can be less than half of
the diameter D of the inlet portion. Preferably, the height H is at least
approximately 25% of the diameter D. In certain other implementations,
the edges defining the exhaust dispersion opening 43 extend to an
elevation above the elevation of axis A. For example, the height H of the
opening 43 can be more than half of the diameter D of the inlet portion
13. Preferably, the height H of the opening 43 is not more than 75% of
the diameter D of the inlet portion.

[0082] In some implementations, the length LO of the opening 43 can
be at least approximately 1.5 times the height H of the opening. In one
specific exemplary implementation, the length LO of the opening 43
can be approximately five times the height H of the opening.

[0083] Although preferably a significant portion of the edges of the
tailpipe 12 defining the exhaust dispersion opening 43 extends
approximately parallel to axis A, it is recognized that in some
embodiments, a significant portion of the edges need not be parallel to
the axis A. For example, the exhaust dispersion opening 43 can have,
among other shapes, a generally inverted V-shaped or semi-circular shaped
profile.

[0084] In some implementations, the exhaust dispersion opening 43 can have
a minimum width W that is at least approximately 50% of the diameter D of
the inlet portion 13 and a maximum width that can be at least
approximately 100% of the diameter D (see FIG. 8). In specific
implementations, the minimum width W can be approximately 75% of the
diameter D of the inlet portion 13 and the maximum width can be
approximately 125% of the diameter D. As shown, the width W of the
opening 43 can be defined as the lateral distance between opposing sides
of the tailpipe adjacent the tailpipe edges defining the opening.

[0085] In some implementations, the length LO of the exhaust
dispersion opening 43 can be at least approximately 1.5 times the width W
of the opening. In a specific exemplary implementation, the length
LO of the opening 43 can be at least approximately 2.5 times the
width W of the opening.

[0086] The operation of the device 10 is shown schematically in FIGS. 7-9.
Exhaust, e.g., exhaust gas, from the engine, indicated generally by arrow
60, flows through the exhaust system of the vehicle or equipment and into
the device 10 via the tailpipe exhaust inlet opening 35 of the tailpipe
12. Referring to FIG. 7, in general terms, the exhaust gas flowing
through the tailpipe 12 can comprise lower, middle and upper portions
indicated generally by directional arrows 67, 69, 71, respectively. The
lower portion 67 is disposed initially at and below the upper edge
defining the exhaust dispersion opening 43 between the second and third
locations 34, 36, respectively, the middle portion 69 is disposed above
the upper edge, and the upper portion 71 is disposed between the portion
of exhaust 69 and an upper internal surface of the inlet section 13.

[0087] As the lower portion of exhaust 67 flows from the tailpipe exhaust
inlet section 13 and into the tailpipe exhaust outlet section 18, it is
quickly dispersed downwardly and laterally from the exhaust dispersion
opening 43.

[0088] As the middle portion of exhaust 69 flows into the tailpipe exhaust
outlet section 18 from the inlet section 13, some of the exhaust is
quickly dispersed through the exhaust dispersion opening 43. The
remaining exhaust of the portion of exhaust 69 continues to flow above
the exhaust dispersion opening 43, while being incrementally expelled
through the exhaust dispersion opening along the axial length of the neck
portion 26 and flare-out side portions 24. Some of the middle portion of
exhaust 69 flows through the exhaust outlet section 18 until it is
redirected by the convex surface of the flow guide divider 22. The flow
guide divider 22 redirects some of the portion of exhaust 69 downwardly
and at an angle with respect to axis A, and some of the portion of
exhaust 69 downwardly and laterally.

[0089] Referring to FIG. 9, the direction of exhaust flow, e.g., exhaust
flow 69, is defined herein as a vector having a lateral component and a
downward component. The lateral components, e.g., lateral component 69a,
of the direction vectors of exhaust flow, e.g., exhaust flow 69, extend
in a direction that is approximately perpendicular to the central axis of
the tailpipe, e.g., axis A, and parallel to a ground plane that is
parallel to and disposed below the exhaust dilution and dispersion device
when the device is attached to a vehicle. The downward components, e.g.,
downward component 69b, of the direction vectors of exhaust flow, e.g.,
exhaust flow 69, extend in a direction that is approximately
perpendicular to the central axis of the tailpipe and the ground plan.
Accordingly, exhaust flow can be described as flowing laterally,
sideways, outwardly or transversely, if the direction vector of the
exhaust flow has a lateral component that is greater than zero.
Similarly, exhaust flow can be described as flowing downwardly, if the
direction vector of the exhaust flow has a downward component that is
greater than zero.

[0090] The upper portion of exhaust 71 flows through the tailpipe outlet
section 18 until it is guided downwardly by and at least partially within
the flow guide channels 30. With the flow guide divider 22 having
increasing interior surface areas and the channels having decreasing
cross-sectional areas, as the upper portion of exhaust 71 flows through
the channels 30, portions of the exhaust 71 are incrementally impacted by
the flow guide divider to redirect these portions of the exhaust 71 flow
outwardly away from divider to be expelled from exhaust dispersion
opening 43 in a lateral direction. Some portions of the exhaust 71 are
not impacted by the flow guide divider and continue to flow within the
channels 30 until dispersed through the exhaust dispersion opening 43 at
the second end 16 of the tailpipe 12.

[0091] The elongate exhaust dispersion opening 43 and the bifurcated end
portion 19 of the device 10 promote a wide multi-directional dispersion
of exhaust gases from the tailpipe 12 and can reduce backpressure in an
exhaust system. More specifically, the generally elongate arcuate shape
of the exhaust dispersion opening 43 in profile and the flow guides 20
and flow guide divider 22 facilitate a substantial portion of exhaust to
be expelled laterally from the exhaust dispersion opening 43 along
approximately, e.g., at least 90% of, the entire length of the exhaust
dispersion opening. In some embodiments, a major portion (e.g., more than
one-third) of the exhaust gases are dispersed laterally. Referring to
FIG. 9, in some implementations, exhaust can be dispersed from the
exhaust dispersion opening 43 in directions within a range about axis A
defined by angle γ. In some implementations, the angle γ can
be approximately 180° or less. In a specific exemplary
implementation, the angle γ can be approximately 90°.

[0092] As mentioned above, the lateral dispersion of exhaust gases
facilitated by the exhaust dilution and dispersion device described
herein promotes rapid decentralization of the exhaust gas exiting the
tailpipe, thus resulting is a quicker reduction of the temperature of
dispersed exhaust at locations away from the tailpipe of the device than
conventional tailpipe configurations.

[0093] Exemplary embodiments of the exhaust dilution and dispersion device
were tested against conventional tailpipes know in the art to illustrate
the enhanced temperature reduction characteristics of the device. The
results and testing conditions of computer simulated and physical tests
for a specific exemplary embodiment of the device described above,
another specific exemplary embodiment of a exhaust dilution and
dispersion device as will be described below, and the conventional
tailpipe are shown in FIGS. 12a-12b. FIG. 12a shows the results of tests
using a computational fluid dynamics (CFD) approach to simulate the
exhaust temperatures under the same testing conditions at various planes
away from the exhaust outlets of the exemplary devices and conventional
tailpipe. FIG. 12b shows the results of tests using a thermocoupled plate
to physically measure the actual exhaust temperature at various planes
away from the exhaust outlets. FIG. 12c shows the results of tests using
a CFD approach to simulate the exhaust temperatures under the
approximately same testing conditions as in the physical tests for
validating the results of the CFD models being tested.

[0094] In all the tests, the exhaust dilution and dispersion devices and
conventional tailpipe were tested in an actual or simulated environment
with no wind and during active regeneration of the turbo-diesel engine to
which the devices and tailpipe were coupled. Other testing conditions,
including the specifications of the device being tested, are indicated in
FIGS. 12a-12c with respect to the particular device or tailpipe being
tested and will be described in more detail below.

[0095] Referring to FIGS. 12a-12c, the exhaust temperature reducing
performance of Device I, i.e., a very specific exemplary implementation
of device 10 shown in FIGS. 1-9, was tested against the exhaust
temperature reducing performance of a conventional tailpipe, such as
tailpipe 42 illustrated in FIGS. 10 and 11.

[0096] Device I had an overall length of approximately 17 inches with the
tailpipe exhaust inlet section 13 having a pipe diameter of approximately
five inches. In this example, the lower edge 40 of the second end 16 of
Device I extended about one-half inch below the lowermost surface of the
exhaust inlet section 13. The angle β of the guide flow divider 22
with respect to axis A was approximately 143°. Device I was made
from, or simulated to be made from, 439 aluminized stainless steel.

[0097] The conventional tailpipe being tested consisted of a length of
circular pipe having a diameter of approximately 5 inches and a
downwardly directed end portion 44 with a circular exhaust outlet 46. The
conventional tailpipe had an overall length of approximately 13 inches
and was made from A787 aluminized steel.

[0098]FIG. 12a shows the testing conditions of a first set of tests run
on the simulated model of Device I and the simulated model of the
conventional tailpipe. The inlet temperature of the exhaust entering the
Device I and tailpipe was set at 650° C., the exhaust flow
velocity through the Device I and tailpipe was set at 70 m/s and the
ambient air temperature was set at 25° C.

[0099] The graphical results of the tests run on the simulated model of
Device I and conventional tailpipe, in the form of color-coded thermal
plots of the exhaust temperatures at a horizontal plane located 5.5
inches (140 mm) away from, i.e., below, the lowermost point of the
outlets of Device I and tailpipe, are shown in FIGS. 13a and 13b,
respectively. As shown, and reported in FIG. 12a, the exhaust being
expelled from Device I (see FIG. 13a) is more widely dispersed than the
exhaust being expelled from the conventional tailpipe (see FIG. 13b).
This wider dispersion of exhaust resulted in a maximum temperature of the
exhaust at the 5.5 inch plane of approximately 305° C. In
contrast, the exhaust dispersion of the conventional tailpipe was more
concentrated, which resulted in a maximum temperature of the exhaust at
the 5.5-inch plane of approximately 525° C. Accordingly, Device I
produced a maximum exhaust temperature that was approximately 42% lower
than the maximum exhaust temperature produced by the conventional
tailpipe under the same conditions. Further, Device I facilitated an
approximately 53% reduction of the exhaust temperature from the exhaust
inlet to the 5.5-inch plane where the conventional tailpipe produced only
a 19% reduction in temperature.

[0100] FIGS. 14a and 14b show thermal plots of the exhaust temperatures
for the simulated Device I and conventional tailpipe obtained during the
same tests as performed above, but at a horizontal plane located 11.8
inches (300 mm) below the lowermost point of the outlets. As shown, and
reported in FIG. 12a, the maximum temperature of the exhaust expelled
from Device I at the 11.8-inch plane was approximately 233° C.
(see FIG. 14a), while the maximum temperature of the exhaust expelled
from the conventional tailpipe at the same plane was approximately
467° C. (see FIG. 14b). In other words, at the 11.8-plane, the
wider dispersion of exhaust produced by Device I resulted in a maximum
exhaust temperature that was approximately 50% lower than the maximum
exhaust temperature produced by the conventional tailpipe under the same
conditions. Further, Device I facilitated an approximately 64% reduction
of the exhaust temperature from the exhaust inlet to the 11.8-inch plane
where the conventional tailpipe produce only a 38% reduction in
temperature.

[0101] As can be recognized from the numerical results of the simulated
tests in FIG. 12a and the graphical results shown in FIGS. 13a, 13b, 14a,
14b, wide multi-directional dispersion of exhaust gas produced by a
exhaust dilution and dispersion device having an elongate exhaust
dispersion opening and bifurcated end portion as described in relation to
FIGS. 1-9, results in a significant drop in the maximum temperature of
the exhaust at a distance away from the device when compared with the
maximum temperature of the exhaust at the same distance away from
conventional tailpipes.

[0102] FIG. 12b shows the testing conditions, including the final results,
of tests conducted on physical implementations approximating Device I and
the conventional tailpipe described above. The actual inlet temperature
of the exhaust entering the Device I and tailpipe was approximately
550° C. and 600° C., respectively, the actual exhaust flow
velocity through the Device I and tailpipe was approximately 18 m/s and
the actual ambient air temperature was approximately 10° C.

[0103] The graphical results of the tests conducted on the physical
implementations of Device I and conventional tailpipe, in the form of
color-coded thermal plots of the measured exhaust temperatures at a
horizontal plane located 6 inches below the outlets of the Device I and
tailpipe are shown in FIGS. 15a and 15b, respectively. As shown, and
reported in FIG. 12b, the actual maximum temperature of the exhaust
expelled from Device I at the 6-inch plane was measured at approximately
198° C. (388° F.) (see FIG. 15a), while the actual maximum
temperature of the exhaust expelled from the conventional tailpipe at the
6-inch plane was measured at approximately 430° C. (806°
F.) (see FIG. 15b). Accordingly, the physical implementation of Device I
produced a maximum exhaust temperature that was 54% lower than the
maximum exhaust temperature produced by the conventional tailpipe at the
same plane under similar conditions. Further, the physical implementation
of Device I facilitated an approximately 64% reduction of the exhaust
temperature from the exhaust inlet to the 6-inch plane where the
conventional tailpipe produce only a 28% reduction in temperature.

[0104] FIGS. 16a and 16b show thermal plots of the exhaust temperatures
for the physical implementation of Device I similar to FIGS. 15a and 15b,
respectively, but measured at a ground plane, e.g., a horizontal plane
located approximately 16 inches below the lowermost point of the outlets.
As shown and reported in FIG. 12b, the maximum temperature of the exhaust
expelled from the physical Device I at the 16-inch plane was measured at
approximately 42° C. (108° F.), while the maximum
temperature of the exhaust expelled from the conventional tailpipe at the
same plane was approximately 203° C. (397° F.).
Accordingly, at the 16-inch plane, the physical implementation of Device
I produced an approximately 79% greater reduction in the maximum exhaust
temperature compared to the physical implementation of the conventional
tailpipe. Further, Device I facilitated an approximately 92% reduction of
the exhaust temperature from the exhaust inlet to the 16-inch plane where
the conventional tailpipe produce only a 66% reduction in temperature.

[0105] A second set of tests using a CFD approach were run on a simulated
model of Device I designed to have the same characteristics as the
physical implementation of Device I used in the physical testing
described above. The CFD tests were modeled to simulate the actual
testing conditions found in the physical tests. The results of the second
set of tests could then be compared to the measured results to validate
the accuracy of the simulated models described above in relation to FIGS.
13a and 14a.

[0106] FIG. 12c shows the testing conditions, including the final results,
and FIGS. 17a and 17b show the results graphically in the form of
color-coded thermal plots for the second set of tests using the CFD
approach. Referring to FIGS. 12c, 17a, and 17b, the maximum simulated
exhaust temperature in the second set of tests for Device I was
approximately 258° C. (531 K) at the 6-inch plane (see FIG. 17a)
and approximately 155° C. (428 K) at the 16-inch plane (see FIG.
17b). Comparing these results with the actual measured temperatures, the
simulated maximum exhaust temperatures were approximately 23% higher at
the 6-inch plane (an approximately 53% reduction versus the inlet exhaust
temperature) and 73% higher at the 16-inch plane (an approximately 72%
reduction versus the inlet exhaust temperature) than the actual measured
exhaust temperatures. Accordingly, the simulated numerical results in
FIG. 12a and graphical results in FIGS. 13a and 14a are validated as
conservative estimates of the actual performance of Device I.

[0107] Referring now to FIGS. 18-22, another exemplary embodiment of an
exhaust dilution and dispersion device for reducing the maximum
temperature of exhaust gas dispersed from the device is shown. Referring
to FIG. 18, exemplary exhaust dilution and dispersion device 110
comprises a tailpipe, or tailpipe portion, 113 that can be coupled to a
vehicle's engine exhaust system to receive exhaust gas from the engine.

[0108] As described above in relation to FIGS. 1-9, the device 110 can be
coupled to an exhaust system of a vehicle or piece of equipment at any of
various locations within or along the exhaust system. The device 110 can
also be mounted to a vehicle or piece of equipment in a variety of
orientations as described above.

[0109] The tailpipe 113 comprises an exhaust inlet section, or portion,
134 extending from a first end 193 in exhaust receiving communication
with an exhaust outlet section, or portion, 150 extending from a second
end 195 opposite the first end.

[0110] The inlet section 134 includes a generally circular inlet opening
135 at the first end of the tailpipe 113. In one exemplary
implementation, the inlet portion 134 comprises a flared portion 139
coextensive with the inlet opening 135. Extending in a downstream, or
exhaust flow, direction, i.e., from the first end 193 towards the second
end 195, the inlet section 134 includes a diffusion section 114 and a
mixing section 116.

[0111] The outlet section 150 includes an exhaust deflection portion 151
and an exhaust dispersion opening 143. Preferably, at least a portion of
the exhaust dispersion opening 143 is coextensive with the exhaust
deflection portion 151. The deflection portion 151 can be downwardly
directed at an angle θ with respect to a central axis B of the
tailpipe 113. More specifically, the angle θ of the outlet section
150 can be described generally as the angle defined between a line, such
as line 191, that is approximately tangential to the outer surface of the
outlet section 150 and the central axis B (see FIG. 20).

[0112] Desirably, inlet portion 134 and the outlet section 150 are
seamlessly connected to form a monolithic one-piece construction.
However, in some implementations, one or more sections of the inlet and
outlet sections 134, 150, respectively, comprise respective individual
sections, such as lengths of tubing coupled together such as by welding.

[0113] As shown in FIG. 19, the exhaust dispersion opening 143 has a
generally elongate shape that faces in a generally downward direction.
The exhaust dispersion opening 143 can extend longitudinally from the
upstream boundary or end of the outlet section 150.

[0114] The exhaust dispersion opening 143 can have one of many alternative
shapes. However, in a desirable form, a portion of the exhaust dispersion
opening 143 has a generally elongate arcuate-shape, or elongate inverted
U-shaped, side profile. For example, referring to FIG. 16, opposing
generally symmetrical edges of the tailpipe 113 defining the illustrated
exhaust dispersion opening 143 extend in the downstream direction
upwardly at an angle relative to axis B from a first location 125
proximate a lower surface of the outlet section 150 toward a second
location 127 away from the lower surface of the outlet section. The
symmetrical edges then extend approximately parallel to axis B in the
downstream direction from the second location 127 to a third location
129. From the third location 129, the edges curve downwardly at an angle
relative to axis B toward end portion 195 from the third location 129 to
a fourth location 133. From the fourth location 133, the edges are
adjoined at the second end 195 of the tailpipe 113.

[0115] In some embodiments, each of the two generally symmetrical edges
extending approximately parallel to axis B between the second and third
locations 127, 129 comprises a substantial portion of the perimeter of
the opening 143, i.e., each edge has a length of at least approximately
15% of the total length LO of the opening 143. In specific
implementations, each edge between the second and third locations 127,
129 can have a length of at least approximately 25% of the total length
LO of the opening 143. The total length LO of the opening 43
can be defined as the distance extending axially along the opening 143
between the first location 125 and the end of the opening proximate the
end 195 of the tailpipe 113.

[0116] In some implementations, the second and third locations 127, 129,
respectively, are at an elevation approximately equal to the elevation of
axis B. Accordingly, in this example, the edges defining the exhaust
dispersion opening 143 between the second and third locations 127, 129
can extend at an elevation approximately equal to the elevation of the
axis B. In other words, the exhaust dispersion opening 143 can have a
height H approximately equal to half a major diameter D of the tailpipe
113, for example, the diameter D of the mixing section 116 (see FIG. 19).

[0117] In certain implementations, the edges of the tailpipe 113 defining
the exhaust dispersion opening 143 extend to an elevation below the
elevation of axis B. For example, the height H of the opening 143 can be
less than half of the diameter D of the tailpipe 113. Preferably, the
height H is at least approximately 25% of the diameter D.

[0118] In certain other implementations, the edges of the exhaust
dispersion opening 143 extend to an elevation above the elevation of axis
B. For example, the height H of the opening 143 can be more than half of
the diameter D of the tailpipe 113. Preferably, the height H of the
opening 143 is not more than 75% of the diameter D of the tailpipe.

[0119] In some implementations, the length LO of the opening 143 can
be at least approximately 1.5 times the height H of the opening. In one
specific exemplary implementation, the length LO of the opening 143
can be approximately five times the height H of the opening.

[0120] In some implementations, the exhaust dispersion opening 143 can
have a width W that is at least approximately 75% of the diameter D of
the tailpipe 113 (see FIG. 22). In specific implementations, the width W
can be at least approximately 100% of the diameter D of the tailpipe 113.

[0121] In some implementations, the length LO of the exhaust
dispersion opening 143 can be at least approximately 1.5 times the width
W of the opening. In a specific exemplary implementation, the length
LO of the opening 143 can be at least approximately 2.5 times the
width W of the opening.

[0122] Although preferably a significant portion of the edges defining the
exhaust dispersion opening 143 extend approximately parallel to the axis
B, it is recognized that in some embodiments, a significant portion of
the edges defining the opening need not be parallel to the axis B. For
example, the exhaust dispersion opening 143 can have, among other shapes,
a generally inverted V-shaped or semi-circular shaped profile.

[0123] Referring again to FIG. 20, the diffusion section 114 of the inlet
section 134 of the tailpipe 113 can have, for example, a generally
frusto-conical shape defining a passageway with a diverging sidewall
moving in the downstream direction, i.e., from right to left in FIG. 20.
In other words, the diffusion section passageway desirably expands such
that the area of the passageway increases along its axial length when
moving in the downstream direction. In some embodiments, the diverging
sidewall extends at an angle of between approximately 5° and
15° relative to axis B. In specific embodiments, the angle is
approximately 10° relative to axis B.

[0124] The mixing section 116 can have a generally cylindrical shape and
define a passageway having a sidewall extending generally parallel to
central axis B of the exhaust dilution and dispersion device 110. In
other words, the cross-sectional area at any given location along the
axial length of the mixing section 116 can be substantially the same.

[0125] As shown schematically in FIG. 20, in operation, exhaust, e.g.,
exhaust gas, from the engine indicated by arrow 160 flows through the
tailpipe 113. The exhaust first flows into the diffusion section 114. The
diverging sidewall of the diffusion 114 section passageway causes the
exhaust, indicated generally by arrows 167, 169, 171, to diffuse or
expand as it flows through the diffusion section. Diffusion or expansion
of the exhaust results in a decrease in the velocity of the exhaust,
which reduces the temperature of the exhaust. From the diffusion section
114, the exhaust flows into the mixing section 116.

[0126] From the mixing section 116, the exhaust flows into the outlet
portion 150 to be eventually expelled through the exhaust dispersion
opening 143. Referring to FIGS. 20 and 21, upon entering the outlet
portion 150, some of the exhaust, e.g., the portion of the exhaust below
the upper edges defining the exhaust dispersion opening 143, e.g., the
edges defining the opening that extend approximately parallel to axis B
in the illustrated embodiment, pass through the exhaust dispersion
opening 143 as indicated generally by directional arrow 167. Some of the
exhaust, e.g., a portion of the exhaust above the upper edges of the
exhaust dispersion opening 143, is not expelled upon entering the outlet
portion 150, but continues to flow through the outlet portion above the
exhaust dispersion opening, while being incrementally expelled through
the exhaust dispersion opening along the axial length of the outlet
portion as indicated generally by directional arrows 169. Yet some of the
exhaust flows through the outlet portion 150 above a majority of the
length LO of the exhaust dispersion opening 143 and is expelled
through the opening near the end 195 of the tailpipe 113 as indicated
generally by directional arrows 171.

[0127] As indicated in FIG. 22, the configuration of exhaust dispersion
opening 143 facilitates lateral dispersion of exhaust indicated generally
by arrows 173 from the exhaust dispersion opening along its axial length.
Lateral dispersion of exhaust refers to dispersion in an outward
direction away from a direction parallel to axis B. The exhaust flowing
through the mixing section 116 is traveling in a direction generally
parallel to axis B of the device 110. As the portion of the exhaust below
the upper edges of the exhaust dispersion opening 140, e.g., the flow
indicated by arrows 167 in FIGS. 20 and 21, flows into the outlet section
150 and just past the leading edge of the exhaust dispersion opening 143,
it is not bounded laterally by the sidewall of the tailpipe 113 and is
thus allowed to flow laterally outwardly away from the tailpipe along the
axial length of the opening. Further, at least some of the mixture
flowing above the upper edges of the exhaust dispersion opening 143,
e.g., the flow indicated by arrows 169 in FIGS. 20 and 21, is dispersed
laterally from the opening. Desirably, a major portion (e.g., more than
one-third) of the exhaust gases is dispersed laterally from the exhaust
dispersion opening 143.

[0128] As can be recognized, the configuration and shape of the exhaust
dispersion opening 143 promotes a wide dispersion of the exhaust into the
ambient air and reduces backpressure. For example, in some embodiments,
exhaust can be dispersed from the exhaust dispersion opening 143 in
directions within an angle range about axis B of approximately
180°. In a specific exemplary implementation, the angle range is
approximately 90°.

[0129] This enhanced dispersion of the exhaust acts to dilute the heated
exhaust gas concentration more quickly and effectively than a
conventional tailpipe. Because the exhaust gas concentration is more
widely dispersed and quickly diluted, more effective mixing of the
exhaust with the ambient air upon exiting the device 110 occurs, which
results in a quicker reduction of the temperature of the exhaust gases as
the gases move away from the device. Consequently, the temperature of the
exhaust gases at specific distances away from the exhaust dispersion
opening 143 is more effectively reduced to meet or exceed industry safety
standards.

[0130] Referring back to FIG. 18, to help further reduce the temperature
of the exhaust received from a vehicle's exhaust system, the device 110
can comprise an ambient air entrainment system 198 to draw ambient air
into the exhaust flow to cool the exhaust flow. For example, the ambient
air entrainment system 198 can comprise a nozzle 112 connected to the
tailpipe 113 via structural connectors, such as gussets 120.

[0131] In the illustrated exemplary implementation, the nozzle 112
comprises a length of tubular pipe having a generally circular
cross-section. The nozzle 112 includes an inlet section 130 that can have
an exhaust inlet opening 131 and be coupled to a portion of an exhaust
system of a vehicle or equipment engine, such as to an exhaust pipe or
muffler of a diesel engine for a truck, by welding or through use of
fasteners or pipe couplings. The inlet section 130 can have a flared
portion for convenience in coupling the nozzle 112 to the exhaust system.

[0132] Preferably, in some implementations of a device 110 having an air
entrainment system 198, the opening 143 has a length LO that is at
least approximately 50% of the length LT of the tailpipe 113 (see
FIG. 19). In some implementations, however, it is recognized that the
length LO of the opening 143 can be less than 50% of the length
LT of the tailpipe 113.

[0133] Each gusset, or connector, 120, in the exemplary form shown,
comprises a length of material having a generally elongate fin-like shape
with a notch 137 intermediate a tailpipe mounting portion 121 and a
nozzle mounting portion 123. The illustrated tailpipe mounting portion
121 has a mounting surface that is coextensive with an outer surface of
the tailpipe inlet section 134 when the gusset 120 is mounted to the
tailpipe. The illustrated nozzle mounting portion 123 has a mounting
surface that is coextensive with an outer surface of the nozzle 113 and
offset radially from, e.g., not coplanar with, the mounting surface of
the tailpipe mounting portion 121 when the gusset 120 is mounted to the
nozzle.

[0134] The gussets 120 couple the nozzle 112 and the tailpipe 113 together
such as by welding the tailpipe mounting portions 121 of the gussets 120
to the outer surface of the tailpipe 113, welding the notches 137 of the
gussets 120 to the flared portion 139 of the tailpipe inlet section 134,
and welding the nozzle mounting portions 123 of the gussets 120 to the
outer surface of the nozzle 112. In the illustrated embodiment, the
gussets 120 extend parallel to axis B of the exhaust dilution and
dispersion device 110.

[0135] Although three gussets 120 are shown in the illustrated embodiment,
it is recognized that fewer or more than three gussets can be used. It is
recognized that alternative coupling structures other than gussets, such
as conventional fasteners can also be used.

[0136] As shown in FIG. 20, the nozzle 112 is partially disposed within
the tailpipe 113. The nozzle 112 has an exhaust accelerating outlet
section 132 opposite the inlet section 130. The exhaust accelerating
outlet section 132 has, in this example, a generally frusto-conical shape
having a sidewall that converges in the exhaust flow direction. In some
embodiments, the converging sidewall of the accelerating outlet section
132 extends at an angle of between approximately 0° and 15°
relative to axis B. In specific embodiments, the angle is approximately
5° relative to axis B.

[0137] The flared or enlarged inlet section 134 of the tailpipe 113, in
this example, also has a generally frusto-conical shape with a side wall
that converges in the exhaust flow direction. The sidewall of the
enlarged inlet section 134 of the tailpipe 113 desirably defines a
passageway having a reduced cross-sectional dimension, such as having
circular cross-sectional areas of decreasing diameters, along its axial
length moving in the exhaust flow direction.

[0138] Desirably, the smallest diameter of the tailpipe inlet section
passageway is greater than the largest outer diameter of the outlet
section 132 of the nozzle 112. In this way, the nozzle 112 can be
insertably mounted within and coaxially with the tailpipe 113 by the
gussets 120 such that an annular ambient air passageway, or opening, 136
is defined between the inner surface of the passageway of the tailpipe
inlet section 134 and an outer surface of the outlet section 132 of the
nozzle 112. An upstream end of the passageway 136 is in air receiving
communication with ambient air (air outside of the device 110) in the
environment and a downstream end of the passageway is in air expelling
communication with an interior of the tailpipe 113. The air passageway,
in alternative embodiments, is other than of an annular configuration.

[0139] As shown schematically in FIG. 20, in operation, exhaust from the
engine flows through the exhaust system (not shown) and into the nozzle
112, as indicated by arrow 160, at a first velocity. The velocity of the
exhaust remains substantially the same until the exhaust flows into the
exhaust accelerating outlet section 132 of the nozzle 112, where the
velocity of the exhaust increases as the exhaust flowing through the
outlet section is compressed due to the converging nature of the sidewall
of the outlet section. The accelerated exhaust exiting the outlet section
132 flows into the tailpipe 113, indicated generally by arrow 162, and
causes a pressure differential with the surrounding ambient air. The
pressure differential creates a vacuum effect to draw in ambient air,
indicated generally by arrows 164, through the ambient air passageway
136. The ambient air at least partially mixes with the exhaust flowing
out of the nozzle 112. The ambient air has a temperature less than the
temperature of the exhaust gas and therefore acts to reduce the overall
temperature of the exhaust.

[0140] In some embodiments, one or more turbulence enhancers can be
utilized to promote turbulence in the exhaust and air flowing through the
device, which enhances mixing of the air and exhaust. In some
embodiments, the turbulence enhancers can be modified gussets, such as
bent, curved or angled gussets. For example, as shown in FIG. 23,
modified gussets 182 are positioned at an angle relative to, or otherwise
non-parallel with, the central axis C of exhaust dilution and dispersion
device 180, which can have features similar to device 110. A portion of
the gussets 182 can penetrate the side wall of the tailpipe and protrude
into the interior of the tailpipe downstream of the ambient air
passageway and within the exhaust flow stream. The portion of the gussets
182 within the exhaust flow stream acts to obstruct the flow of exhaust
and entrained air and induce turbulence in the exhaust and air flowing
through the tailpipe.

[0141] In some embodiments, separate from, or in addition to modified
gussets, turbulence enhancing vanes, protrusions or baffles can be
mounted within the interior of the exhaust dilution and dispersion device
and positioned to obstruct the exhaust and air flowing through the
tailpipe.

[0142] After mixing with the ambient air drawn through the passageway 136,
the exhaust and air flows into and through the diffusion and mixing
sections 114, 116, respectively, and is dispersed through the exhaust
dispersion opening 143 in a manner similar to that described above. More
specifically, as it pertains to a tailpipe coupled to an air entrainment
system for drawing in ambient air, as the exhaust and air mixture flows
through the diffusion section 114, the diffusion or expansion of the
mixture results in a decrease in the velocity of the mixture, which
facilitates further mixing of the ambient air with the exhaust to further
reduce the effective temperature of the exhaust.

[0143] The mixing section allows the exhaust and air mixture to flow at a
constant velocity, which helps to stabilize the exhaust and air mixture
exiting the diffusion section. Stabilization of the exhaust and air
mixture can reduce negative pressure, or back pressure, within the
expansion section, restrict undesirable separation of the exhaust and air
mixture, and promote further mixing of the exhaust and air prior to the
mixture being dispersed into the surrounding environment.

[0144] Referring back to FIGS. 12a-12c, testing similar to that performed
on Device I was conducted on Device II, i.e., a very specific exemplary
implementation of device 110 shown in FIG. 18-22. Device II had an
overall length of approximately 30 inches and the inlet section 134 had a
pipe diameter of approximately 6 inches. Device II also was made from, or
simulated to be made from 439 aluminized stainless steel.

[0145] As shown in FIG. 12a, a simulated model of Device II was tested
using the same testing conditions as was used for the first set of
simulated testing of Device I. The graphical results of the first set of
simulated tests of Device II in the form of color coded thermal plots of
the exhaust temperatures at the 5.5-inch plane and the 11.8-inch plane
are shown in FIGS. 24a and 24b, respectively. As shown in FIGS. 24a and
24b, and reported in FIG. 12a, the maximum temperature of the exhaust
being expelled from Device II at the 5.5-inch plane and 11.8-inch plane
was approximately 467° C. and 346° C.; respectively.
Accordingly, Device II facilitated an approximately 38% reduction and an
approximately 47% reduction of the exhaust temperature from the exhaust
inlet to the 5.5-inch plane and 11.8-inch plane, respectively.

[0146] When compared with the results of testing the simulated
conventional tailpipe as shown in FIGS. 13b and 14b, and reported in FIG.
12a, a exhaust dilution and dispersion device described above in relation
to FIGS. 18-22, e.g., Device II, can provide a significantly greater
reduction of the temperature of the exhaust at distances away from the
device outlet than conventional tailpipes. For example, Device II
provided an approximately 11% and 26% greater reduction in the
temperature of the exhaust at the 5.5-inch and 11.8-inch planes,
respectively.

[0147] FIG. 12b shows the testing conditions, including the final results,
of tests conducted on physical implementations approximating Device II.
The actual inlet temperature of the exhaust entering the Device II was
approximately 520° C., the actual exhaust flow velocity through
the Device II was approximately 40 m/s and the actual ambient air
temperature was approximately 18° C.

[0148] The graphical results of the tests conducted on the physical
implementations of Device II in the form of color-coded thermal plots of
the measured exhaust temperatures at the 6-inch plane and the 15.5-inch
plane are shown in FIGS. 25a and 25b, respectively. As shown, and
reported in FIG. 12b, the actual maximum temperature of the exhaust
expelled from Device II at the 6-inch plane was measured at approximately
310° C. (590° F.) (see FIG. 25a) and at the 15.5-inch plane
was measured at approximately 186° C. (367° F.) (see FIG.
25b). Accordingly, the physical implementation of Device II produced a
maximum exhaust temperature that was approximately 28% and approximately
8% lower than the maximum exhaust temperature produced by the
conventional tailpipe at approximately the same respective planes under
similar conditions. Further, the physical implementation of Device II
facilitated an approximately 40% and 64% reduction of the exhaust
temperature from the exhaust inlet to the 6-inch plane and 15.5-inch
plane, respectively.

[0149] A second set of tests using a CFD approach were run on a simulated
model of Device II designed to have the same characteristics as the
physical implementation of Device II used in the physical testing
described above. The CFD tests were modeled to simulate the actual
testing conditions found in the physical tests. The results of the second
set of tests could then be compared to the measured results to validate
the accuracy of the simulated models described above in relation to FIGS.
24a and 24b.

[0150] FIG. 12c shows the testing conditions, including the final results,
and FIGS. 26a and 26b show the results graphically in the form of
color-coded thermal plots for the second set of tests using the CFD
approach. Referring to FIGS. 12c, 26a, and 26b, the maximum simulated
exhaust temperature in the second set of tests for Device II was
approximately 369° C. (642 K) at the 6-inch plane (see FIG. 26a)
and approximately 242° C. (515 K) at the 16-inch plane (see FIG.
26b). Comparing these results with the actual measured temperatures, the
simulated maximum exhaust temperatures were approximately 16% higher at
the 6-inch plane (an approximately 29% reduction versus the inlet exhaust
temperature) and 23% higher at the 16-inch plane (an approximately 54%
reduction versus the inlet exhaust temperature) than the actual measured
exhaust temperatures. Accordingly, the simulated numerical results in
FIG. 12a and the graphical results in FIGS. 24a and 24b are validated as
conservative estimates of the actual performance of Device II.

[0151] Referring to FIG. 27, according to one exemplary embodiment,
exhaust dilution and dispersion device 10 can comprise an ambient air
entrainment system 50 similar to that described above for exhaust
dilution and dispersion device 110 of FIGS. 18-22 to enhance the
temperature reducing capabilities of the device 10. Like the air
entrainment system 198 of device 110, the air entrainment system 50 of
the device shown in FIG. 27 comprises a nozzle 12 connected to the
tailpipe 13 via structural connectors, such as gussets 20. Further,
although the tailpipe 13 of device 10 does not show a diffusion section
and a mixing section, such as described above in relation to the tailpipe
112 of device 110, it is recognized that in some implementations, the
tailpipe 12 can have a diffusion section and a mixing section to
facilitate cooling of the exhaust and/or mixing of ambient air drawn into
the tailpipe via an air entrainment system 50 with exhaust flowing
through the tailpipe. Also, although not specifically shown, the
embodiment of device 10 shown in FIG. 27 can include turbulence
enhancers, such as turbulence enhancing gussets, as described above in
relation to FIG. 23.

[0152] In some embodiments of the exhaust dilution and dispersion device
10 having an ambient air entrainment system 50, the opening 43 has a
length LO that is preferably at least approximately 50% of the
length LT of the tailpipe 13 (see FIG. 2). In some implementations,
however, it is recognized that the length LO of the opening 43 can
be less than 50% of the length LT of the tailpipe 13.

[0153] The nozzle 12 can comprise a length of tubular pipe having a
generally circular cross-section. Like the nozzle 112 of device 110, the
nozzle 12 includes an inlet section 30 that has an exhaust inlet opening
31 and is coupled to an exhaust pipe, muffler or other portion of the
exhaust system a vehicle a piece of equipment. Although not shown, the
inlet section 30 can have a flared portion for convenience in coupling
the nozzle 12 to the exhaust system. The nozzle 12 is partially disposed
within the tailpipe by the gussets 20 and can interact with the tailpipe
inlet section 13 to define an ambient air passageway or opening as
described above. The flow of exhaust can create a vacuum effect to draw
in ambient air through the air passageway. Although not required, in some
implementations, the nozzle can have an exhaust accelerating outlet
section opposite the inlet section 30 to accelerate the exhaust.
Acceleration of the exhaust can enhance the vacuum effect that is
responsible for drawing in ambient air through the passageway. Air drawn
through the passageway mixes with and cools the exhaust in a manner
similar to that described above in relation to the device 110 of FIGS.
18-22.

[0154] As was described above, providing a device with an elongate exhaust
dispersion opening for providing a wide multi-directional dispersion of
exhaust gas from the opening can also help to reduce backpressure in a
vehicle's exhaust system. For example, as shown in FIG. 28, backpressure
was measured at various time intervals during the running of a
turbo-diesel engine for an exhaust dilution and dispersion device similar
to the exemplary embodiment shown in FIGS. 18-20 and for a conventional
tailpipe, such as shown in FIGS. 10 and 11. The backpressure in the
exhaust system employing the exhaust dilution and dispersion device
remained lower than the backpressure in the exhaust system using the
conventional tailpipe during a substantial majority of the engine running
time. Accordingly, providing an elongate exhaust dispersion opening as
described herein can not only reduce the maximum temperature of exhaust
expelled from the device at distances away from the device, but it can
help facilitate a reduction in backpressure within the vehicle's exhaust
system.

[0155] In certain implementations, multiple exhaust dilution and
dispersion devices, such as devices 10, 110, 180, can be coupled to a
vehicle's engine exhaust system, such as in a vertically stacked
formation behind the vehicle.

[0156] The components of the exhaust dilution and dispersion device
described herein can be made from a steel alloy, such as aluminated
steel, or, in particularly high exhaust gas temperature applications,
aluminated stainless steel. Other suitable durable heat tolerant
materials can also be used.

[0157] Various manufacturing techniques can be used to make the exhaust
dilution and dispersion device described herein, such as, for example,
stamping, hydroforming, casting, machining, forging and molding. In some
exemplary methods of manufacturing the exhaust dilution and dispersion
device, the tailpipe can be formed from a length of pipe. The exhaust
dispersion opening can be formed by cutting out or removing a section of
the pipe while the exhaust deflection portion can be bent into the
desired shape using hand tools and/or machines.

[0158] In view of the many possible embodiments to which the described
principles may be applied, it should be recognized that the illustrated
embodiments are only preferred examples and should not be taken as
limiting the scope of the application. Rather, the scope is defined by
the following claims. We therefore claim as our invention all that comes
within the scope and spirit of these claims.